Method of treating yarn, thread, and the like



Feb. 3, 1953 H. Y. JENNINGS 2,627,103

METHOD OF TREATING YARN, THREAD AND THE LIKE Filed Dec. 6. 1947 INVENTOR. HARLEY JENN/NGS.

ATTORNEKS.

Patented Feb. 3, 1953 METHOD OF TREATING YARN, THREAD, AND THE LIKE Harley Y. Jennings, Danville, Va., assignor to Dan River Mills, Incorporated, Danville, Va., a corporation of Virginia Application December 6, 1947, Serial No. 790,145

1 claim. l

This invention relates to the art of treating yarns, thread, cord or the like for the purpose of changing its strength characteristics and also its elasticity or residual stretch. It is known, for example, in the Jennings Patent No. 2,220,958 that the ultimate breaking strength of a spun thread may be greatly increased by subjecting it after spinning to a moistening bath with or without the addition of binding material, and permitting the natural or added binders to set while the thread is maintained under a tension close to its untreated breaking strength. In the continuous treatment of threads and yarns for this purpose, the variation and irregularity in the residual stretch of the thread along its length makes it difficult to maintain proper tension without frequently exceeding the breaking strength of the weak portions of the thread as they pass through the apparatus.

since the improvement in breaking strength is greatest when the applied tension in the thread is highest, it is desirable to maintain as high a tension as possible during treatment. On the other hand, if the tension is maintained too high, the frequency of breaks in the thread increases.

In the development work leading up to the present invention, it has been found that untreated thread has rather wide variations in its residual stretch, that is, the percentage elongation under any given tension, and thatI this variation is very much greater than the Variation of tensile strength.

In previous apparatus used for treating threads, the tensioning mechanism has been so constructed that variations in the residual stretch of the untreated thread interfere with maintaining constant tension and thus further aggravate the frequency of breakages because of the resulting variations in applied tension. The mechanism could not be set for as high a tension as the thread would stand because of the resulting variations in applied tension; in other words, the mechanism could not be set for as high a tension as the thread will stand because of the necessity of allowing for tolerance in applied tension necessitated by variations in residual stretch or elongation as well as tolerance necessary for variations in breaking strength of the thread. This means that maximum benefits of the tensioning process could not be obtained in commercial practice and with previous apparatus it was necessary to treat the thread at a tension considerably lower than the maximum desirable.

'It is an object of the present invention to provide an improved method and apparatus for treating threads, yarns and the like under tensionin which variations in residual stretch of the untreated thread are compensated for priorto the tensioning treatment.

A further object is to provide a method and apparatus of this character in which the thread is brought up to its maximum tension for treatment in two stages, in the first of which the speed of travel of the thread is automatically varied as variations occur in the residual stretch of a particular section so that the thread may enter the second stage at a more constant speed, thus permitting higher constant tension to be maintained.

Another object of the present invention is to provide an improved apparatus for supplying a continuous length of thread from a supply spool or bobbin under a constant tension.

Figure 1 is a diagrammatic view of a thread treating apparatus incorporating a preferred form of the present invention.

Figure 2 is a fragmentary top view of a portion of the apparatus in Figure l.

Figure 3 is a fragmentary view on a larger scale of the supply reel brake mechanism, with the brake mechanism parts shown in reversed position with respect to the supply reel.

Figure 4 is a section on line 4--4 of Figure 3.

Referring now to Figure 1, the apparatus is illustrated diagrammatically as comprising a frame I0 carrying an upstanding spindle I2 upon which a supply bobbin or spool I4 is freely rotatable. Also rotatable on the spindle I2 is a brake disc I 6 having a pin I8 (Figure 3) projecting from its upper surface and adapted to be received in a suitable recess in the lower flange of the bobbin I4 thus causing the bobbin and brake disc to rotate in unison. The frame I0 also carries a brake arm 20 which is pivotally mounted on a stud 22, secured to the frame by means of a bushing 24 to which the arm 20 is secured. The bushing 24 also carries a follower arm 26, the latter fis formed of relatively thin spring steel so as to be slightly yieldable and carries a roller follower 28 at its outer end and adapted to contact the body of the thread on the bobbin.

A suitable light tension spring 30 is attached to the brake arm 20 by a pin 32 and serves to yieldably urge the follower 28 into contact with the spool. The brake arm 20 carries a small, ilat brake shoe 34 preferably on a ball and socket joint 36 and is adapted to frictionally engage the lower surface of the brake disc I6. The brake shoe 34 is of limited area and is rather small in relation to the diameter of the disk I6.

A compression spring 38 is mounted on stud 22 below the bushing 24 and is adjustable by means of a threaded nut 40 so as to urge the brake shoe 34 into contact with the disk I6 with an adjustable braking force. The frame I0 also carries by suitable supporting means, not illustrated, a multiple-groove sheave block set generally designated 42. This block set comprises a pair of multiple-grooved sheaves 44 geared together by suitable gearing 46. One of the sheave blocks 44 has a brake disk 48 at one end which 3 cooperates with a pair of non-rotatable braking disks 50 and 52. The latter are adapted to be clamped together by means of any suitable clamping mechanism, for example, a Sylphon bellows 54 which is adapted to expand or contract between the movable disk 52 and a stationary plate or support 56, the brake disk 50 being supported from the plate 56 by means of bolts 58.

It will be understood that any suitable retarding mechanism may be applied at the sheave block set 42, the mechanism illustrated being typical of devices for this purpose. The retarding mechanism may be automatically controlled by the tension in the thread as it leaves the sheave block set 42, and for this purpose a pulley 60 is mounted on a weighted lever 62 pivoted to the frame at 64. 'I'he lever 62 is adapted to bear upon another Sylphon bellows 14 which is connected to the bellows 54 by a conduit 16. The two bellows and the conduit being filled with a liquid, the force applied by the lever 62 is transmitted to the movable brake plate 52 and is thus under control of the tension in the thread passing over the pulley 68.

Also mounted on the frame IIJ by suitable supports, not illustrated, is a second multiple sheave block set generally designated 'I8 which is driven at a constant speed by suitable gearing or chain and sprocket mechanism not illustrated. The sheave block 'i8 has a large number of falls of thread and adjacent to the falls suitable drying means such as infra-red lamps 88 are preferably provided, the heat of drying being sufcient to substantially set or cure the bonding material within the yarn or thread while still under maximum tension. The thread leaving the blocks 18 passes directly to a take-up-spool 82 mounted on the frame I and driven by yielding friction means in the well-known manner.

In operation, a bobbin of thread, yarn, cord or the like to be treated after first being subjected to suitable soaking treatment with a bonding agent is placed on the spindle I2 and engaged with the pin I8. The end is then threaded through the first multiple sheave set 42 preferably in figure 8 loops and from there passes through the pulley 60 and through the multiple falls 'i8 to the take-up bobbin 82 as clearly illustrated in Figure 1. The drive mechanism is then started and the threadis pulled through the apparatus.

It will be seen that inthe main treatingV section between sheave blocks 42 and take-up spool 82, tensionY may be applied and preferably determined and controlled by the brake mechanism at sheaves 44. The drive for the sheaves 'I8 applies sufhcient tension to partially supportV the weighted arm 62 and thus relieve some of the braking force applied through bellows 'I4 and 54 to the brake disk 52. This causes the sheaves 44 to rotate and pull the thread 01T from the supply bobbin I4. This in turn is controlled bythe brake shoe 34 acting on the brake disk I6.

The braking force applied to the surface of the disk I6 is maintained constant by the action of the spring 38. However, the braking torque4 is varied as the thread unwinds from the bobbin I4 since the roll 28 follows the contour of the thread as it decreases in diameter and progressively shifts the brake arm- 2liv toward thecenter of the brake disk I6. Thus the radius at which the braking force of the'shoe34 is applied; is variedj or decreased in proportion to the decrease in diameter of the bobbin I4.. This in turn maintains va constant linear tension. in the thread between bobbin I4 and the sheave set 42.

The degree of tension in the main treating section is adjustable by shifting the weights along the weighted arm 62 and is preferably set very close to the breaking strength of the thread beiner treated. The tension maintained ahead of the sheave set 42 is determined by the setting of spring 38. This is preferably so adjusted as to maintain a much smaller degree of tension which may be in the neighborhood of 5 to 60 percent of the tension maintained in the main treating section. It will be seen, however, that this tension is sucient to produce considerable elongation in the thread. Thus when variations in the residual elongation occur, the bobbin I4 will temporarily change its speed to correspond so that the thread enters the first multiple sheaves 42 with most of the variation in residual stretch compensated for or smoothed out.

Thus, when the thread passes to the main treating section, these variations have been removed to a large degree and the tension maintained in the heating section may be much higher than would be the case if the thread were fed to the main treating section without being pre-tensioned.

It will be seen that in the second tension zone or main treating section the general action is that the units 42 and '53 act as continuous locking members to create a locked zone, whereby the critical tension is applied by the Weight arm 62, thus eliminating the unequal tension resulting when the critical tension is attempted to be maintained by slippage.

It will be understood that saturation or treatment of the yarn or thread may take place in the first tension zone, between the bobbin I4 and the unit 42, instead of ahead of the bobbin.

What is claimed is:

The method of treating continuously moving yarn, thread and the like to increase its strength, which comprises the steps of impregnating the thread with a bonding agent, initially applying a tension to the thread in a iirst zone suiiicient to smooth out inequalities in its residual stretch, gripping the thread at spaced points while moving to create a locked zone and stretching the thread while wet in this locked zone to a point short of4 breaking, and setting the bonding agent by application of heatr while maintaining a tension substantially the' same as that exerted in the locked zone.

HARLEY Y. JENNINGS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STA-TES PATENTS Number Name Date 1,676,797 Nyman July 10, 1928 1,803,129 Palmer Apr. 28, 1931 2,103,042v Sachtleben Dec. 21, 1937 2,156,9231 Picard May 2,1939 2,212,691 Kershaw: Aug. 27, 1940 2,220,958 Jennings Nov. 12, 1940 2,226,135 Newton et al. Dec 24, 1940 2,289,232v Babcock July 7, 1942 2,364,467 Nickerson Dec. 5,. 1944 2,365,069' Grimes Dec. l2, 1944 2,381,398 Bosomworth Aug. 7, 1945 2,381,670 Kurkjian Aug. 7, 1945 2,398,787 Hansen Apr. 23, 1946 2,444,064 Philipp June 29, 1948 2,553,374 Kahn May l5, 1951 

